public class Hello {
        public static void main(String[] args) {
                System.out.println("Hello world");
                String s1 = "abc";
                String s2 = "abc";
                System.out.println(s1 == s2);

                String s3 = new String("abc");
                String s4 = new String("abc");
                System.out.println(s3 == s4);
                System.out.println(s3.equals(s4));

                System.out.println(3 + 4 + "abc");
                System.out.println("abc" + 3 + 4);
        }
}
